Characters in Survival Index have five Attributes that correspond to a body "part" (in actuality, to a body ability). These parts are Head, Arms, Core, Legs, and Spirit. Each part has five levels of damage; when a part sustains the fifth damage level it becomes inoperable (with consequences depending upon the part). The game uses a simple dice mechanic to determine outcomes in critical situations.
The game is distributed as a three-page PDF file; the third page contains several character record sheets. The game layout allows each page to be cut into six index cards for distribution (a play on the "index" of Survival Index).